Polycondensation catalyst

ABSTRACT

Condensation polymers of high molecular weight, such as polyesters, polyureas, and polyamides, are usually prepared at temperatures of 200° C. or greater. However, by utilizing the catalyst system of the present invention condensation polymers can be synthesized at much lower temperatures. These catalyst systems are comprised of (1) a silicon-phosphorus composition which contains at least one divalent oxygen atom which is bonded directly to a tetravalent silicon atom and a trivalent or pentavalent phosphorus atom; and (2) at least one acid acceptor. For example, P(OSiR 3 ) 3  wherein R can be an aliphatic or aromatic hydrocarbon radical, can be used in conjunction with a basic solvent as a catalyst system. Polymeric agents having pendant diphenylphosphine dichloride groups can also be used in conjunction with an acid acceptor as a catalyst system.

BACKGROUND OF THE INVENTION

High molecular weight condensation polymers can be prepared by utilizingconventional polymerization techniques at elevated temperatures. Forexample, nylon (66) can be prepared by polycondensing (polymerizing)hexamethylene diamine with adipic acid at a temperature of about 280° C.and polybisphenol A carbonate can be prepared by polycondensingbisphenol A with diphenyl carbonate at a temperature of about 300° C.Condensation polymers of high molecular weight, such as polyesters,polyureas, and polyamides, are generally prepared at temperatures inexcess of 200° C. The utilization of high temperatures in such synthesistechniques is, of course, an energy intensive process.

SUMMARY OF THE INVENTION

The present invention relates to a technique for preparing condensationpolymers, such as polyamides, polyureas, and polyesters, which utilizesmild conditions at relatively low temperatures. Since low temperaturesare utilized in this polymerization technique substantial energy savingscan be attained. This technique utilizes a catalyst system which iscomprised of (1) a silicon-phosphorus composition which contains atleast one divalent oxygen atom which is bonded directly to a tetravalentsilicon atom and a trivalent or pentavalent phosphorus atom; and (2) atleast one acid acceptor. Such polymerizations are normally carried outat a temperature of 0° C. to 150° C.

The present invention more specifically relates to a catalyst systemwhich is particularly useful for the synthesis of condensation polymerswhich is comprised of (1) at least one silicon-phosphorus compositionwhich contains at least one divalent oxygen atom which is bondeddirectly to a tetravalent silicon atom and a trivalent or pentavalentphosphorus atom; (2) at least one acid acceptor; and (3) at least onehalogenated organic compound.

The present invention also reveals a catalyst system which isparticularly useful in synthesizing condensation polymers which iscomprised of (1) at least one polymeric agent having pendantdiphenylphosphine dichloride groups; and (2) at least one acid acceptor.

The present invention also discloses a process for the synthesis of apolyester comprising polymerizing at least one dicarboxylic acid with atleast one aromatic glycol in the presence of (1) a silicon-phosphoruscomposition which contains at least one divalent oxygen atom which isbonded directly to a tetravalent silicon atom and a trivalent orpentavalent phosphorus atom; and (2) an acid acceptor. The presentinvention further relates to a process for the synthesis of a polyestercomprising polymerizing at least one dicarboxylic acid with at least onearomatic glycol in the presence of (1) at least one polymeric agenthaving pendant diphenylphosphine dichloride groups; and (2) at least oneacid acceptor. These catalyst systems can also be used in the synthesisof polyesters from aromatic hydroxyl acids.

DETAILED DESCRIPTION OF THE INVENTION

There are numerous benefits that can be realized by utilizing thepolymerization techniques of the present invention. Since lowtemperatures are utilized thermal degradation of the polymer beingsynthesized can be virtually eliminated. Such low temperature techniquesalso avoid many side reactions which occur at higher temperatures. Thelow temperature polymerization techniques of the present invention alsomake possible the synthesis of new polymers, for instance, polymerswhich contain thermally unstable moieties. Accordingly, crosslinkablepolyesters and polyamides can be prepared which contain unstable groupssuch as aldehydes and thiols. It should also be possible to preparecrosslinkable polymers which contain double or triple bonds using thecatalyst systems disclosed herein. By utilizing such low temperaturesynthesis techniques, substantial energy savings are, of course, alsorealized.

The silicon-phosphorus compounds which are used in the catalystcompositions of this invention contain at least one divalent oxygen atomwhich is bonded directly to a tetravalent silicon atom and to atrivalent or pentavalent phosphorus atom. Such silicon-phosphoruscompounds have the general structural formula: ##STR1## wherein R¹, R²,R³, R⁴, R⁵, R⁶ and R⁷ can be virtually any type of chemical moiety. Forinstance, R¹, R², R³, R⁴, R⁵, R⁶, and R⁷ can be alkyl groups whichcontain from 1 to 20 carbon atoms, aryl groups which contain from 1 to20 carbon atoms, alkylaryl groups which contain from 1 to 20 carbonatoms, hydrogen atoms, organometallic groups, or inorganic moieties.Additionally, R⁴, R⁵, R⁶ and R⁷ can be halogen atoms with the provisothat no more than 2 of such groups are halogen atoms. Chlorine, bromine,and iodine are particularly useful halogens in such silicon-phosphoruscompounds. These groups can have a cyclic structure. In fact, thesemoieties can be multiply bonded to the silicon and/or phosphorus atoms.The number of possible compositions and structures for suchsilicon-phosphorus compounds is virtually unlimited.

Silicon-phosphorus compounds having the structural formula:

    P(OSiR.sub.3).sub.3

wherein R is an alkyl group containing from 1 to 20 carbon atoms arevery effective in the catalyst systems of the present invention. In mostcases the alkyl groups in such compounds will contain from 1 to 8 carbonatoms. For instance, tris(trimethyl silil) phosphite has been used inthe catalyst systems of this invention with great success. R can alsorepresent aryl groups or alkylaryl groups which contain from 1 to 20carbon atoms. Silicon-phosphorus compounds having the structuralformula:

    R.sup.1 --P(OSiR.sub.3).sub.2 or ##STR2## wherein R, R.sup.1 and R.sup.2 are selected from the group consisting of alkyl groups containing from 1 to 20 carbon atoms, aryl groups containing from 1 to 20 carbon atoms, and alkylaryl groups containing from 1 to 20 carbon atoms, are also useful in the catalyst systems of the present invention. In most cases, R, R.sup.1, and R.sup.2 will contain from 1 to 8 carbon atoms.

Silicon-phosphorus compounds having the structural formula:

    O═P(OSiR.sub.3).sub.3

wherein R is selected from the group consisting of alkyl groups,alkylaryl groups and aryl groups containing from 1 to 20 carbon atomscan also be used in such catalyst systems. Similarly, silicon-phosphoruscompounds having the structural formula:

    X.sub.2 P(OSiR.sub.3).sub.3 or X.sub.2 P--OSiR.sub.3

wherein X is a halogen atom and wherein R is selected from the groupconsisting of alkyl groups, alkylaryl groups and aryl groups containingfrom 1 to 20 carbon atoms, can also be used.

Polymeric silicon-phosphorus compositions can also be utilized. Forinstance, polymers having the structural formula: ##STR3## wherein R isan alkyl group, an aryl group or an alkylaryl group and wherein n is aninteger can be used in such catalyst systems. In most cases R will be analkyl group containing from 1 to 8 carbon atoms or a phenol group.Generally, n will be an integer from about 10 to about 1000. Anotherpolymeric silicon-phosphorus composition that can be used has thestructural formula: ##STR4## wherein n is an integer and wherein R¹, R²,R³, R⁴, R⁵, and R⁶ can be the same or different and are selected fromalkyl groups, alkylaryl groups and aryl groups which contain from 1 to20 carbon atoms. In most cases, n will be an integer from about 10 toabout 1000.

In addition to the silicon-phosphorus composition, these catalystsystems also contain an acid acceptor and a halogenated organiccompound. The acid acceptors which can be used are typically organicbases which have a pKa of at least 5. Most commonly such organic baseshave a pKa within the range of 5 to 12. The halogenated organiccompounds which can be used generally contain at least one carbon atomwhich has at least two halogen atoms bonded directly to it. Preferablysuch halogenated organic compounds will contain one or more carbon atomswhich have at least three halogen atoms bonded directly to them, such astrichloromethane. Halogenated organic compounds which have a carbon atomwith four halogen atoms bonded directly to it, such as carbontetrachloride and carbon tetrabromide, are most preferred for use in thecatalyst systems of the present invention. Silicon-phosphorus compoundswhich contain halogen atoms can serve the dual purpose of providing boththe silicon-phosphorus compound component and the halogenated organiccompound component of the catalyst system.

The acid acceptor and the silicon-phosphorus compound are employed inmolar amounts which are approximately equal to the molar amount ofmonomers utilized in the polymerization. Typically the polymerizationwill be conducted in an inert organic solvent. Any inert organic solventwhich provides sufficient solubility can be utilized. Aromatic organicsolvents, such as pyridine or alkyl substituted pyridines (picoline orlutidine) will typically be employed because they normally provide goodsolubility. Dimethylformamide is an example of an aliphatic liquid thatprovides good solubility.

The reaction mediums utilized in the polymerizations of this inventionare comprised of the inert organic solvent, the catalyst system and themonomers being polymerized. Such reaction mixtures normally contain fromabout 0.05 to 1 moles of monomer per liter of solution. However, it ispermissible to utilize the maximum amount of monomer which is soluble inthe particular organic solvent being used. More typically such reactionmixtures will contain from about 0.1 to about 0.5 moles of monomer perliter of solution.

The polymerizations of this invention will normally be carried out at atemperature between about 0° C. and about 150° C. Preferably suchpolymerizations will be conducted at a temperature of from 50° C. to 80°C.

Catalyst systems which utilize a polymeric agent having pendant diphenylphosphine dihalide groups in conjunction with an acid acceptor can alsobe used. Such pendant diphenylphosphine dihalide groups can berepresented by the structural formula: ##STR5## wherein X represents ahalide atom. The polymeric backbone to which such diphenylphosphinedihalide groups are bonded is not of great importance. In fact, thediphenylphosphine dihalide groups can be bonded to either inorganic orpolymeric organic substances. For instance, inorganic glasses which havesuch diphenylphosphine dihalide groups bonded to them work well in suchcatalyst systems. Organic polymers, such as polystyrene can also be usedto support pendant diphenylphosphine dihalide groups. Normally thediphenylphosphine dihalide will be diphenylphosphine dichloride. Thetriphenylphosphine dihalide transforms into a triphenylphosphine oxideafter the polycondensation and the triphenylphosphine oxide can beconverted back to a triphenylphosphine dihalide by treatment with eitheran oxalyl halide ##STR6## or a carbonyl dihalide ##STR7## at atemperature from 0° C. to 50° C.

The polyamides made in accordance with the present invention areprepared by reacting one or more diamines with one or more dicarboxylicacids. The polyesters made in accordance with the present invention areprepared by reacting one or more aromatic diols with one or moredicarboxylic acids. The term "aromatic diols" as used herein is alsodeemed to include aromatic glycol ethers (diethers) and aromaticpolyether glycols.

The dicarboxylic acids utilized in the preparation of such polyestersand polyamides are normally alkyl dicarboxylic acids which contain from4 to 36 carbon atoms, aryl dicarboxylic acids which contain from 8 to 20carbon atoms, and alkyl substituted aryl dicarboxylic acids whichcontain from 9 to 22 carbon atoms. The preferred alkyl dicarboxylicacids will contain from 4 to 12 carbon atoms. Some representativeexamples of such alkyl dicarboxylic acids include glutaric acid, adipicacid, pimelic acid, and the like. The preferred aryl dicarboxylic acidscontain from 8 to 16 carbon atoms. Some representative examples of aryldicarboxylic acids are terephthalic acid, isophthalic acid, andorthophthalic acid. The preferred alkyl substituted aryl dicarboxylicacids contain from 9 to 16 carbon atoms.

The diamine component utilized in the preparation of polyamides isnormally a diamine that contains from 2 to 12 carbon atoms. Preferreddiamines normally contain from 2 to 8 carbon atoms with preferreddiamines containing from 4 to 8 carbon atoms. Some representativeexamples of diamines that can be utilized in the synthesis of polyamidesinclude ethylene diamine, hexamethylenediamine,bis(4-amino-cyclohexyl)-methane, o-phenyldiamine, m-phenylenediamine,p-phenylenediamine, 1,2-diamino-3,5-dichlorobenzene,1,3-diamino-2,5-dichlorobenzene, 1,2-diamino-4-methylbenzene,1,4-diamino-2-isopropylbenezene, 1,3-diaminopropane, 1,4-diaminobutane,and the like.

The diol component utilized in making aromatic polyesters in accordancewith the present invention are aromatic diols which normally containfrom 6 to 20 carbon atoms. Bisphenol A is a good example of an aromaticdiol that can be used. Some other aromatic diols which can be usedinclude 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene(resorcinol), 1,4-dihydroxybenzene (hydroquinone),1,2-dihydroxy-3,5-dimethylbenzene, 1,2-dihydroxy-4,5-dimethylbenzene,1,4-dihydroxy-2,3-dimethylbenzene, 2,4-dihydroxy-1-ethylbenzene,2,4-dihydroxy-1-hexylbenzene, 1,4-dihydroxy-2-iodobenzene,2,4-dihydroxy-1-isobutylbenzene, 1,2-dihydroxy-4-isopropylbenzene,1,4-dihydroxy-2-isopropylbenzene,1,4-dihydroxy-2-isopropyl-5-methylbenzene,1,3-dihydroxy-2-methylbenzene, 2,4-dihydroxy-1-(3-methyl-butyl)benzene,2,4-dihydroxy-1-(4-methylpentyl)benzene, 1,3-dihydroxy-4-pentylbenzene,1,3-dihydroxy-5-pentylbenzene, 1,4-dihydroxy-2,3,5,6-tetrabromobenzene,1,3-dihydroxy-2,4,5,6-tetrachlorobenzene,1,4-dihydroxy-2,3,5,6-tetramethylbenzene, and the like.

The polyesters and polyamides which are prepared utilizing the catalystsystem of the present invention can be made in a manner so as to inducebranching. Such branching is normally attained by utilizing a branchingagent in the synthesis of the polyester or polyamide. Such branchingagents normally contain three or more functional groups and preferablycontain three or four functional groups. The reactive groups may becarboxyl or aliphatic hydroxyl. The branching agent can contain bothtypes of groups. Examples of acidic branching agents include trimesicacid, trimellitic acid, pyromellitic acid, butane tetracarboxylic acid,naphthalene tricarboxylic acids, cyclohexane-1,3,5-tricarboxylic acids,and the like. Some representative examples of hydroxyl branching agents(polyols) include glycerin, trimethylol propane, pentaerythritol,dipenterythritol, 1,2,6-hexane triol, and 1,3,5-trimethylol benzene.Generally, from 0 to 3 percent of a polyol containing from 3 to 12carbon atoms will be used as the branching agent (based upon the totaldiol component).

This invention is illustrated by the following examples which are merelyfor the purpose of illustration and are not to be regarded as limitingthe scope of the invention or the manner in which it can be practiced.Unless specifically indicated otherwise, parts and percentages are givenby weight.

EXAMPLE 1

Tris(trimethyl silil) phosphite (TMSP) was synthesized by reactingtrimethyl silil chloride with phosphorus acid in tetrahydrofuran in thepresence of triethyl amine. This reaction is illustrated as follows:##STR8## This reaction was carried out by adding 166 grams of trimethylchlorosilane to a solution containing 40 grams of phosphorus acid. Thesolvent used in this experiment was a mixture of 400 ml oftetrahydrofuran and 1,600 ml of dry diethyl ether. One hundredfifty-five grams of triethyl amine was added drop by drop to thesolution formed over a period of 1.5 hours. The solution was thenrefluxed for 6 hours. After filtering a white crystal, solvents wereevaporated in vacuum and a viscous residue was distilled under vacuum.The distilled product was heated at 140°-150° C. for 18 hours in thepresence of 3 grams of sodium metal and was distilled in vacuum. Atheoretical yield of TMSP of 43 percent was attained. The synthesis ofTMSP was confirmed by elemental and spectroscopic analysis.

EXAMPLE 2

Tris(triphenyl silil) phosphine (TPSP) was synthesized by dissolving1.76 grams of phosphorus and 5.06 grams of a metal alloy of sodium andpotassium in 250 ml of monoglyme. The solution prepared was refluxed for20 hours. A solution of 500 ml of monoglyme containing 50 grams oftriphenylchlorosilane was added to the solution, followed by refluxingfor 30 hours. The solution prepared was filtered while it was hot andthen cooled with ice. A white crystal was separated out of the solutionwhich was filtered off. The crystal was recrystallized from monoglymethree times and dried in vacuum. The crystals recovered were identifiedby elemental and infrared analysis as being TPSP which had a meltingpoint of 225°-227° C. The yield attained in this reaction was 59% oftheoretical.

EXAMPLE 3

A polycondensation reaction of para-aminobenzoic acid was carried out in10 ml. of pyridine in the presence of 0.0048 moles of TMSP and 0.006moles of hexachloroethane at room temperature. The solution preparedcontained 0.004 moles of para-aminobenzoic acid. The reaction took placein a slightly exothermic state at room temperature. The polymerizationwas allowed to proceed at room temperature for a period of 2 hoursfollowed by heating at 80° C. for 2 hours. The reaction product waspoured into 300 ml of acetone and a precipitated polymer was collectedby filtration, followed by washing with excess methanol and drying invacuum. The polymer recovered was identified by infrared analysis asbeing polyaminobenzoic acid. The yield attained was 21.8 percent oftheoretical.

EXAMPLE 4

The procedure utilized in Example 3 was repeated in this experimentexcept that iodoform was used in place of the carbontetrabromideutilized in Example 3. In this experiment, polyaminobenzoic acid wasrecovered with the yield being 57.4 percent. This example clearlyillustrates that the catalyst system of the present invention can beutilized in making polyamides at low temperatures with good yields.

EXAMPLE 5

The procedure utilized in Example 4 was repeated in this experimentexcept that para-hydroxybenzoic acid was polymerized in place of thep-aminobenzoic acid polymerized in Example 4. The polyester synthesizedin this experiment was poly-p-hydroxybenzoic acid with the yieldattained being 35.6 percent. The polyester produced was confirmed byinfrared analysis to be poly-p-hydroxybenzoic acid.

EXAMPLE 6

The procedure utilized in Example 5 was repeated in this experimentexcept for the fact that the polymerization was carried out in thepresence of 5 cubic centimeters of N-methyol-2-pyrrolidone. In thisexperiment yield was increased to 55.3 percent. The polyester preparedwas, again, confirmed by infrared analysis to be polyhydroxybenzoicacid.

EXAMPLE 7

Aromatic polyesters of high molecular weight were prepared by the directpolycondensation reaction of dicarboxylic acids and bisphenols orhydroxybenzoic acids by using triphenylphosphine dichloride as acondensing agent. Triphenylphosphine dichloride transforms intotriphenylphosphine oxide after the polycondensation and thetriphenylphosphine oxide can be easily converted back totriphenylphosphine dichloride by using either oxalyl chloride orphosgene gas at room temperature. This allows for a convenient means ofrecycling the initiator system.

Initiator systems in which triphenylphosphine dichloride is fixed on apolymeric support would be very advantageous to industrial applicationsbecause a continuous process for the synthesis of aromatic polyesters orpolyamides becomes possible by designing the process in such way that amonomer solution passes through a column of polymeric initiatorscontaining triphenylphosphine dichloride units where the directpolycondensation takes place within the column, and resulting polymerscan be eluded out of the column. After the saturation of the initiatoractivity, the triphenylphosphine oxide formed can be converted back totriphenylphosphine dichloride again by passing oxalyl chloride gas intothe column. This recycling system for the initiator column makes thesemi-continuous synthesis of polyesters or polyamides possible byalternating polymer synthesis and the conversion of triphenylphosphineoxide back to triphenylphosphine dichloride.

In this experiment triphenylphosphine dichloride was bound topolystyrene by swelling 41.8 g of polystyrene beads which werecrosslinked with 2% divinylstyrene in 250 ml. of nitrobenzene and thenadding 59.6 g of a solution containing 47% boron trifluoride in diethylether.

One hundred twenty-eight grams of bromine was then added in a dropwisefashion over a period of 30 minutes. The contents of the solution formedwere allowed to react for 20 hours at room temperature. The beads werethen separated and washed with various mixtures of dichloromethane andmethyl alcohol. These mixtures of dichloromethane and methanol were madeprogressively richer in dichloromethane content. The ratio ofdichloromethane to methyl alcohol in the solutions utilized containedratios of dichloromethane to methyl alcohol of 9:1, 3:1, 2:3, 3:1, and9:1. The beads were finally washed with pure dichloromethane and werethen dried. The yield of brominated polystyrene was determined to be68.7 grams by elemental analysis.

A portion of 18.5 g of the brominated polystyrene was swelled in 450 mlof tetrahydrofuran and 44 g of chlorodiphenyl phosphine in 150 mltetrahydrofuran were added. 3.2 g of metallic lithium were added intothe solution which was stirred at room temperature for 18 hours. Afterthe lithium was separated by filtration, the solution was heated underrefluxing for 4.5 hours. 300 ml of methanol was added into the solutionand the beads were completely washed with a mixed solution ofdichloromethane and methanol and dried.

The beads fixed with triphenylphosphine units were obtained in a yieldof 23.9 g. It was determined by elemental analysis that almosttheoretical amounts of triphenylphosphine units were incorporated intothe polystyrene beads.

A portion of the beads produced (20 g) were swelled in 60 ml of asolution of dichloromethane and methanol (equal volume ratios) and 80 gof peracetic acid solution obtained from 31% hydroperoxide and aceticanhydride, were added drop by drop with cooling and the reaction wascontinued for 4 hours at room temperature in order to oxidizetriphenylphosphine units. The beads containing triphenylphosphine oxideunits were dipped into 100 ml of monochlorobenzene containing 10 g ofoxalic chloride and the solution was stirred for 5 hours at roomtemperature so as to convert triphenylphosphine oxide units intotriphenylphosphine dichloride units. The beads were washed withdichloromethane (CH₂ Cl₂) completely and dried. Yield of the beads was24.9 g. The beads produced contained pendant diphenylphosphinedichloride groups and had the structural formula: ##STR9##

EXAMPLE 8

Polystyrene beads containing pendant diphenylphosphine dichloride groupswere also synthesized by utilizing a Grignard reaction. In this examplea portion of 14.6 g of magnesium powder was reacted with 3 ml ofethylbromide in 10 ml of tetrahydrofuran (THF) under a nitrogenatmosphere. 41 g of p-chlorostyrene in 75 ml THF was added to theGrignard solution over a period of one hour at a temperature within therange of 45°-50° C. The reaction mixture was added drop by drop to themixed solution of monochlorodiphenyl phosphine (55.6 g) in 200 ml THFwith the solution being kept in the temperature range of 5°-10° C. Thereaction mixture was stirred at room temperature for one hour after theaddition was completed. The reaction mixture was poured into 300 ml ofcold water containing 49.5 g of ammonium chloride and the THF layer wasseparated from the aqueous solution. The THF solution was dried overanhydrous sodium sulfate in the presence of 0.37 g of t-butyl catechol.The THF solution was concentrated to about 200 ml, followed by pouringit into 700 ml of n-hexane and by separating the polymer from thesolution.

After evaporating the THF, an oily product was obtained, which wasrecrystallized from ethanol to yield p-styryldiphenylphosphine. Thep-styryl diphenylphosphine obtained was polymerized in 50 ml of benzeneat 60° C. for 116 hours in the presence of 0.05 g of AIBN and 9.86 g ofpoly(p-styryl diphenylphosphine) were recovered by pouring the polymersolution into excess methanol, followed by washing with methanol and bydrying in vacuum. The procedure utilized to obtain poly(p-styryldiphenylphosphine dichloride) was the same as the procedure specified inExample 7.

EXAMPLE 9

In this experiment glass beads containing pendant diphenyl phosphinedichloride groups were prepared. In this procedure a portion of 50 g ofglass beads of 40 mesh sizes was soaked with 200 ml of THF containing7.2 g of triphenylphosphine dichloride (0.02 mol) and 2.02 g oftriethylamine (0.02 mol). The soaking procedure was continued for oneday at room temperature. The glass beads were separated by filtrationand washed repeatedly by acetonitrile to remove triethylamine salt,followed by drying in vacuum. Elemental analysis of the glass beads wasdifficult, but indicated the existence of carbon (2.5%) and hydrogen(0.7%) with P (color reaction with molybdenum).

EXAMPLES 10-16

In this series of experiments the initiator systems prepared in Examples7, 8 and 9 were utilized in the polymerization of a copolyester ofterephthalic acid, isophthalic acid, and bisphenol A. In this series ofexperiments 11.5 g of one of the initiators containing pendantdiphenylphosphine dichloride groups was added to a 100 ml flask. Inaddition to this 30 ml of monochlorobenzene was also added. Previously,the polymeric initiators were crushed to 40 mesh size. 2.49 g ofterephthalic acid and isophthalic acid was added and the suspensionformed was heated under reflux conditions for 5 minutes under a nitrogenatmosphere, followed by cooling to room temperature. Then 3.42 g ofbisphenol A was dissolved in the suspension. The polymerizations wereinitiated by adding 6.07 g of triethyl amine. The suspension was stirredand heated under reflux conditions for one hour. 50 ml of chloroform wasthen added to the suspension and the polymeric initiators were filteredoff. The separated polymeric initiators were repeatedly washed withmonochlorobenzene. Filtered and washed solutions were combined and anexcess amount of methanol was added to the combine solutions in order toseparate the polymers. The separated polymers were washed with methanol,followed by drying in vacuum.

The solvent used in these polymerizations, the origin of the polymericinitiator, the specific monomer concentration utilized, and the polymeryield attained are identified in Table I:

                  TABLE I                                                         ______________________________________                                        Ex-                          Monomer                                          am-  Initiator Made          Concentration                                    ple  in Example  Solvent     (moles/liter)                                                                           Yield                                  ______________________________________                                        10   7           chlorobenzene                                                                             0.15      75%                                    11   7           chlorobenzene                                                                             0.375     65%                                    12   7           chloroform  0.5       55%                                    13   7           chlorobenzene                                                                             1.0       74%                                    14   8           chlorobenzene                                                                             0.15      80%                                    15   8           chloroform  0.15      71%                                    16   9           chlorobenzene         20%                                    ______________________________________                                    

As can be determined by reviewing Table I, the catalysts which weresupported on polystyrene and the catalyst which was supported on glassall initiated satisfactory polymerizations. In fact, the polymericinitiators utilized in this series of experiments were treated withoxalyl chloride utilizing the method described in Example 7 and werethen used again to catalyze additional polymerizations. The activity ofthe catalysts dropped slightly on subsequent polymerizations. However,it was determined that these supported catalysts could be regeneratedand used in subsequent polymerizations. This series of experimentsclearly demonstrates the feasibility of using such polymeric initiatorsin semi-continuous polymerizations on a commercial basis at lowtemperatures.

Variations in the present invention are possible in light of thedescriptions of it provided herein. It is, therefore, to be understoodthat changes can be made in the particular embodiments described whichwill be within the full intended scope of the invention as defined bythe following appended claims.

What is claimed is:
 1. A catalyst system which is particularly usefulfor the synthesis of condensation polymers which is comprised of (1) atleast one silicon-phosphorus compound which contains at least onedivalent oxygen atom which is bonded directly to a tetravalent siliconatom and a trivalent or pentavalent phosphorus atom; (2) an acidacceptor; and (3) a halogenated organic compound.
 2. A catalyst systemwhich is particularly useful in synthesizing condensation polymers whichis comprised of (1) at least one polymeric agent having pendant diphenylphosphine dihalide groups; and (2) at least one acid acceptor.
 3. Aprocess for the synthesis of a polyester comprising polymerizing atleast one dicarboxylic acid with at least one aromatic glycol in thepresence of (1) a silicon-phosphorus composition which contains at leastone divalent oxygen atom which is bonded directly to a tetravalentsilicon atom and a trivalent or pentavalent phosphorus atom; (2) an acidacceptor: and (3) at least one halogenated organic compound.
 4. Aprocess for the synthesis of a polyamide which comprises polymerizing atleast one dicarboxylic acid with at least one diamine in the presence of(1) a silicon-phosphorus composition which contains at least onedivalent oxygen atom which is bonded directly to a tetravalent siliconatom and a trivalent or pentavalent phosphorus atom: (2) an acidacceptor: and (3) a halogenated organic compound.
 5. A process for thesemi-continuous synthesis of a polyester which comprises (1)polymerizing at least one dicarboxylic acid with at least one aromaticglycol in the presence of (a) at least one substrate having pendantdiphenylphosphine dichloride groups and (b) at least one acid acceptor,at a temperature between about 0° C. and 150° C.: (2) allowing saidpolymerization to continue until a polyester is formed with asubstantial amount of the pendant diphenylphosphine dichloride groupsbeing converted to pendant diphenylphosphine oxide groups; (3) treatingthe pendant diphenylphosphine oxide groups produced with a memberselected from the group consisting of oxalyl chloride and phosgene underconditions which are sufficient to convert the pendant diphenylphosphineoxide groups back to regenerated pendant diphenylphosphine dichloridegroups: and (4) polymerizing additional dicarboxylic acids withadditional aromatic glycols in the presence of the regenerated pendantdiphenylphosphine dichloride groups.
 6. A catalyst system as specifiedin claim 1 wherein said acid acceptor is an organic base which has a pKaof at least
 5. 7. A catalyst system as specified in claim 6 wherein saidhalogenated organic compound contains at least one carbon atom which hasat least two halogen atoms bonded directly to it.
 8. A catalyst systemas specified in claim 7 wherein said silicon-phosphorus compound has astructural formula selected from the group consisting of: ##STR10##wherein R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are selected from the groupconsisting of alkyl groups which contain from 1 to 20 carbon atoms, arylgroups which contain from 1 to 20 carbon atoms, alkylaryl groups whichcontain from 1 to 20 carbon atoms, hydrogen atoms, organometallicgroups, and inorganic moieties; and wherein R⁴, R⁵, R⁶ and R⁷ canfurther be selected from the group consisting of halogen atoms with theproviso that no more than 2 of the members selected from the groupconsisting of R⁴, R⁵, R⁶ and R⁷ are halogen atoms.
 9. A catalyst systemas specified in claim 8 wherein said organic base has a pKa within therange of 5 to 12 and wherein said halogenated organic compound containsat least one carbon atom which has at least 3 halogen atoms bondeddirectly to it.
 10. A catalyst system as specified in claim 9 whereinsaid silicon-phosphorus compound has the structural formula P(OSiR₃)₃wherein R is an alkyl group containing from 1 to 20 carbon atoms.
 11. Acatalyst system as specified in claim 10 wherein R is an alkyl groupcontaining from 1 to 8 carbon atoms.
 12. A catalyst system as specifiedin claim 9 wherein said silicon-phosphorus compound has a structuralformula selected from the group consisting of: ##STR11## wherein R, R¹and R² can be the same or different and are selected from the groupconsisting of alkyl groups containing from 1 to 20 carbon atoms, arylgroups containing from 1 to 20 carbon atoms, and alkylaryl groupscontaining from 1 to 20 carbon atoms.
 13. A catalyst system as specifiedin claim 9 wherein said silicon-phosphorus compound has the structuralformula O═P(OSiR₃)₃ wherein R is selected from the group consisting ofalkyl groups containing from 1 to 20 carbon atoms, aryl groupscontaining from 1 to 20 carbon atoms, and alkylaryl groups containingfrom 1 to 20 carbon atoms.
 14. A catalyst system as specified in claim 9wherein said silicon-phosphorus compound has a structural formulaselected from the group consisting of X₂ P(OSiR₃)₃ and X₂ P-OSiR₃wherein X represents a halogen atom and wherein R is selected from thegroup consisting of alkyl groups containing from 1 to 20 carbon atoms,aryl groups containing from 1 to 20 carbon atoms, and alkylaryl groupscontaining from 1 to 20 carbon atoms.
 15. A catalyst system as specifiedin claim 14 wherein said halogen atom is selected from the groupconsisting of chlorine atoms, bromine atoms and iodine atoms.
 16. Acatalyst system as specified in claim 9 wherein said silicon-phosphoruscompound has the structural formula: ##STR12## wherein R is selectedfrom the group consisting of alkyl groups containing from 1 to 20 carbonatom, aryl groups containing from 1 to 20 carbon atoms, and alkylarylgroups containing from 1 to 20 carbon atoms; and wherein n is an integerfrom about 10 to about 1,000.
 17. A catalyst system as specified inclaim 16 wherein R represents an alkyl group containing from 1 to 8carbon atoms.
 18. A catalyst system as specified in claim 9 wherein saidsilicon-phosphorus compound has the structural formula: ##STR13##wherein n is an integer from about 10 to about 1000 and wherein R¹, R²,R³, R⁴, R⁵ and R⁶ can be the same or different and are selected from thegroup consisting of alkyl groups containing from 1 to 20 carbon atoms,aryl groups containing from 1 to 20 carbon atoms, and alkylaryl groupscontaining from 1 to 20 carbon atoms.
 19. A catalyst system as specifiedin claim 18 wherein R represents an alkyl group containing from 1 to 8carbon atoms.
 20. A catalyst system as specified in claim 2 wherein saidpolymeric agent has the structural formula: ##STR14## werein n is aninteger and wherein X represents a halogen atom.
 21. A catalyst systemas specified in claim 20 wherein n is an integer from about 10 to about1,000.
 22. A process as specified in claim 3 wherein said process isconducted at a temperature from 50° C. to 80° C. and wherein said acidacceptor is an organic base having a pKa of at least
 5. 23. A process asspecified in claim 22 wherein said halogenated organic compound containsat least one carbon atom which has at least three halogen atoms bondeddirectly to it.
 24. A process for the semi-continuous synthesis of apolyester which comprises (1) polymerizing at least one dicarboxylicacid with at least one aromatic glycol in the presence of (a) at leastone substrate having pendant diphenylphosphine dihalide groups and (b)at least one acid acceptor, at a temperature between about 0° C. and150° C.; (2) allowing said polymerization to continue until a polyesteris formed with a substantial amount of the pendant diphenylphosphinedihalide groups being converted to pendant diphenylphosphine oxidegroups: (3) treating the pendant diphenylphosphine oxide groups producedwith a member selected from the group consisting of oxalyl halides andcarbonyl dihalides under conditions which are sufficient to convert thependant diphenylphosphine oxide groups back to regenerated pendantdiphenylphosphine dihalide groups; and (4) polymerizing additionaldicarboxylic acids with additional aromatic glycols in the presence ofthe regenerated pendant diphenylphosphine dihalide groups.
 25. A processas specified in claim 24 wherein said acid acceptor is an organic basehaving a pKa of at least
 5. 26. A catalyst system which is particularlyuseful in synthesizing condensation polymers which is comprised of (1)glass beads having pendant diphenyl phosphine dihalide groups: and (2)at least one acid acceptor.
 27. A catalyst system as specified in claim1 wherein the molar ratio of the acid acceptor to the silicon-phosphoruscompound is trom 0.8 to 1.5 and wherein the molar ratio of thehalogenated organic compound to the silicon-phosphorus compound is from0.8 to 1.5.
 28. A process as provided in claim 3 wherein the molar ratioof the silicon-phosphorus composition to the total amount ofdicarboxylic acids and aromatic glycols present is from 1.0 to 1.5;wherein the molar ratio of the acid acceptor to the total amount ofdicarboxylic acids and aromatic glycols present is from 1.0 to 1.5; andwherein the molar ratio of said halogenated organic compounds to thetotal amount of dicarboxylic acids and aromatic glycols present is from1.0 to 1.5.
 29. A process as provided in claim 4 wherein the molar ratioof the silicon-phosphorus composition to the total amount ofdicarboxylic acids and diamines present is from 1.0 to 1.5; wherein themolar ratio of the acid acceptor to the total amount of dicarboxylicacids and diamines present is from 1.0 to 1.5: and wherein the molarratio of said halogenated organic compounds to the total amount ofdicarboxylic acids and diamines present is from 1.0 to 1.5.
 30. Acatalyst system as specified in claim 2 wherein the molar ratio of acidacceptor to pendant diphenyl phosphine dihalide groups is within therange of 0.8 to 1.5.
 31. A process as specified in claim 24 wherein themolar ratio of pendant diphenyl phosphine dihalide groups to the totalmolar amount of dicarboxylic acids and aromatic glycols is within therange of 1.0 to 1.5 and wherein the molar ratio of acid acceptor to thetotal molar amount of dicarboxylic acids and aromatic glycols is withinthe range of 1.0 to 1.5.